While I don't have a Xense, I imagine the highest audio quality will still be much the same as the Essence. That being:
2 Channel (for your stereo headphones)
PCM 44.1KHz (Based off the sample rate used the most. If your audio collection is a higher rate, set it accordingly)
Set Analog Out to Headphones, The highest audio quality would be to push 600ohms out, however if you are not extremely careful running it, you can ruin your headphones or cause hearing damage. I would suggest just matching to the headphones ( High Gain +12Db for 64~300 ohms)
Turn SPDIF Out off (the PCM check box)
The only DSP mode I run is Hi-Fi (the HF button)
Effect, FlexBass and mixer are untouched.

That setup is based on 2channel headphones/to a Stereo, and would be much different if you went with surround headphones / speakers